South Korea has been enacting more stringent punishments for violent sexual crimes which appear to be on the rise in the country. As the government is recommending castration as a possible solution one citizen is doing his part to prevent these awful crimes.

His name is Hong Gwang Ui, a 43 year-old father of a four year old son, and using his knowledge as an engineer for the military he crafted a simple device which sets off an alarm if within 30 meters of a convicted sex offender.